Rothamsted Research, Harpenden, Herts, UK.
Pest Manag Sci. 2013 Apr;69(4):499-506. doi: 10.1002/ps.3400. Epub 2012 Sep 12.
It has been reported previously that piperonyl butoxide (PBO) can inhibit both P450 and esterase activity. Although the method by which PBO combines with cytochrome P450 has been identified, the way in which it acts as an esterase inhibitor has not been established. This paper characterises the interactions between PBO and the resistance-associated esterase in Myzus persicae, E4.
After incubation with PBO/analogues, hydrolysis of 1-naphthyl acetate by E4 is increased, but sequestration of azamethiphos is reduced. Rudimentary in silico modelling suggests PBO docks at the lip of the aromatic gorge.
PBO binds with E4 to accelerate small substrates to the active-site triad, while acting as a blockade to larger, insecticidal molecules. Structure-activity studies with analogues of PBO also reveal the essential chemical moieties present in the molecule.
先前已有报道称，增效醚（PBO）可以抑制细胞色素 P450 和酯酶的活性。虽然已经确定了 PBO 与细胞色素 P450 结合的方式，但它作为酯酶抑制剂的作用方式尚未确定。本文描述了增效醚（PBO）与烟粉虱 E4 中抗性酯酶之间的相互作用。
用 PBO/类似物孵育后，E4 对 1-萘乙酸酯的水解增加，但对丙硫磷的隔离减少。初步的计算机模拟表明，PBO 位于芳香峡谷的边缘。
PBO 与 E4 结合，加速小分子底物到达活性三联体，同时对较大的、杀虫的分子起阻塞作用。增效醚（PBO）类似物的结构活性研究也揭示了该分子中存在的必要化学部分。
